People who sleep in the same bed often have different thermal needs. Conventional blankets, however, can only provide a uniform degree of thermal protection. A blanket may be adequate for one of the sleepers but too hot or too cold for the other. The blanket may even be unsatisfactory for both sleepers.
The prior art does include multilayer blankets comprising leaves attached to a centrally located hinge. However the nature and construction of the hinge greatly limits the flexibility and convenience of these blankets. For example, U.S. Pat. No. 4,069,526, by Deikel describes a blanket system comprising a full-size base layer covering the double bed and two half-size leaves which are hinged to the base layer by means of two zippers running along the center of the base layer. This design can only accommodate two leaves because of the limitations inherent in the zipper hinge mechanism. Furthermore, each leaf needs to carry a zipper side complementary to the zipper side mounted in the base layer. In addition, leaves can only be mounted in a particular orientation because each side of the attaching zipper must operate in the same direction. These restrictions limit the number of layer combinations. In addition, the hardness of the zipper can detract from the softness of the blanket.
In U.S. Pat. No. 5,664,269, by Broder, the hinge mechanism is implemented by having each leaf comprised of two layers, each one of these layers being attached at the hinge to an adjacent layer in a daisy chain fashion. This construction provides a very limited number of combinations.
The approach taken by Marquette in U.S. Pat. No. 3,508,285, makes use of hook-and-loop fasteners at the hinge. Marquette's approach limits the number of panels to the number of hook-and-loop strips.
U.S. Pat. No. 6,311,347, Limardi et al makes use of buttons to attach two half blankets. This approach is limiting in the number of layers that can be attached. Furthermore, overlapping such leaves creates regions of double thickness.
Further features, aspects, and advantages of the present invention over the prior art will be more fully understood when considered with respect to the following detailed description and claims.